1. Field of the Invention
The invention relates to a magnetic head comprising at least an inductive-type magnetic transducer for writing and a method of manufacturing the same.
2. Description of the Related Art
In recent years, performance improvement in thin film magnetic heads has been sought in accordance with an increase in areal density in a hard disk drive. As a thin film magnetic head, a composite thin film magnetic head has been widely used. A composite thin film magnetic head has a configuration in which a recording head with an inductive-type magnetic transducer for writing and a reproducing head with a magnetoresistive device (also referred to as MR device in the followings) for reading-out are stacked.
A recording head is comprised of, for example, a top pole and a bottom pole which are magnetically coupled in one end and are provided sandwiching a write gap in between, and a coil for generating magnetic flux. The top pole and the bottom pole have a uniform width (a uniform width area) identical to each other in a region near the write gap layer closer to a recording-medium-facing surface (air bearing surface) facing a magnetic recording medium (simply referred to as a recording medium in the followings). Thereby, a xe2x80x9cmagnetic pole portionxe2x80x9d for determining the recording track is formed.
For example, xe2x80x9cspiral structurexe2x80x9d in which a coil is wound around a core two-dimensionally (in a plane), rendering the top pole, the bottom pole or the contact of the top and bottom pole the center, and xe2x80x9chelical structurexe2x80x9d in which a coil is wound around the top pole and the bottom pole are known as coil structure. As an example to which these coil structures are applied discloses a structure in which Japanese unexamined Patent Application Publication No. Hei 5-242429, a helical conductive coil formed of a bottom stripe conductive film and a top stripe conductive film is wound around the top magnetic core in a thin film magnetic head comprising a top magnetic core and a bottom magnetic core facing each other. Also, Japanese Utility Model No. 3033043 discloses a configuration in which, a thin film magnetic head comprises a first core and a second core facing each other, a plurality of spiral coil layers which is wound around the first core clockwise (or counterclockwise) while being wound around the second core counterclockwise (or clockwise) is provided in a layered structure, while being connected to each other. Furthermore, Japanese unexamined Patent Application Publication No. Hei 5-101337 discloses a configuration in which, in a thin film magnetic head comprising a top thin film magnetic core and a bottom thin film magnetic core facing each other, a helical coil is wound around the bottom thin film magnetic core and a helical coil wound around the top thin film magnetic core are coupled with a spiral coil in between.
In a thin film magnetic head, for example, magnetic flux generates when a current flows through the coil at the time of operation of writing information. The generated magnetic flux is propagated to a uniform width area of the top pole which forms a part of the magnetic pole portion via propagation path (referred to as a magnetic path in the followings) of the magnetic flux, which is formed of the top pole and the bottom pole. The magnetic flux propagated to the uniform width area further reaches the tip of the air bearing surface. The magnetic flux reached the tip of the uniform width area leaks outside near the write gap. Thereby, a signal field for writing generates. The recording medium is partially magnetized by the signal field and information is written.
In recent years, for example, miniaturization of coils are sought in order to miniaturize thin film magnetic heads. In order for coils to be miniaturized, the helical structure in which a small region is occupied by the coil is more appropriate as the coil structure than the spiral structure with a two-dimensional spread. It is thought that the coil structure can be more miniaturized by making spaces between the turns of the coils narrower.
However, a thin film magnetic head of the related art has a problem that, because of the following reasons, long manufacturing time is required, so that yield is decreased. For example, high forming precision is required to make spaces between the turns of coils narrower so that the coils are miniaturized. In such a case, the manufacturing process of coils becomes complicated in order to maintain formation with high precision. Therefore, it requires a long time to manufacture a thin film magnetic head. Also, if the forming precision of the coils is not sufficient or there is a small shift in the forming precision at the time of forming the coils, short circuit or the like occurs because of contact between the turns of the coils. As a result, yield of the thin film magnetic head may be decreased. In short, in the related art, it has been difficult to properly achieve miniaturization of coils and improving yield at the same time.
The above-mentioned problems are not particular ones of a thin film magnetic head. Other types of magnetic heads that have the same structure (two magnetic substances facing each other and a coil for generating magnetic flux) as the thin film magnetic head, have the same problems, too.
The invention has been designed to overcome the foregoing problems. An object of the invention is to provide a thin film magnetic head in which the manufacturing time can be shortened and yield can be improved while miniaturizing coils, and a method of manufacturing the same.
A magnetic head of the invention comprises: two magnetic substances magnetically coupled to each other, which are extendedly formed in a direction away from a recording-medium-facing surface facing a recording medium, including two magnetic poles facing each other with a gap in between facing the recording medium; and a coil extendedly formed along in the extended direction of the two magnetic substances including a first winding unit wound around one of the two magnetic substances in a predetermined direction and a second winding unit wound around the other magnetic substances of the two magnetic substances in the opposite direction of the predetermined direction; and an insulator which isolates the coil from the two magnetic substances. In the magnetic head, the coil is in a form of continuum in which the first winding unit and the second winding unit are alternatively coupled.
In the magnetic head of the invention, the coil is in a form of continuum in which the first winding unit and the second winding unit are alternatively coupled. Thereby, portion of the coil which requires high forming precision decreases.
In a magnetic head of the invention, at least the gap, the two magnetic substances, the coil and the insulator may be formed of a thin film.
A method of manufacturing a magnetic head of the invention comprises: two magnetic layers magnetically coupled to each other, which are extendedly formed in a direction away from a recording-medium-facing surface facing a recording medium, including two magnetic poles facing each other with a gap layer in between facing the recording medium; and a thin film coil extendedly formed along the extended direction of the two magnetic layers including a first winding unit wound around one of the two magnetic layers in a predetermined direction and a second winding unit wound around the other magnetic layer of the two magnetic layers in the opposite direction of the predetermined direction; and an insulator which isolates the coil from the two magnetic layers. In the method, a plurality of elements composing the thin film coil is stacked in order so that the thin film coil is formed to be in a form of continuum in which the first winding unit and the second winding unit are alternatively coupled.
In a method of manufacturing a magnetic head of the invention, a plurality of elements composing the thin film coil is stacked in order so that the thin film coil is formed to be in a form of continuum in which the first winding unit and the second winding unit are alternatively coupled.
Other and further objects, features and advantages of the invention will appear more fully from the following description.